1. Field of the Invention
The invention relates to an image scanning apparatus that scans images on a document and to an apparatus using the image scanning apparatus.
2. Description of Related Art
A conventional image scanning apparatus has a document platen on which a document can be placed, and a cover configured to cover the document on the platen (for example, JP2006-87008). With such an image scanning apparatus, an operator places the document on the platen, aligns a side of the document to a side of the platen, and then closes the cover over the document to hold the document at a predetermined position.
However, some documents are distorted, e.g., curled, rolled, or bent. Such a document, when placed on the platen, does not lie flat in complete contact with the platen. Therefore, it is difficult to place the document at the predetermined position on the platen.
To overcome the problem, there is an image scanning apparatus that has one side of the platen having a portion (hereinafter “a document retaining part”) configured to capture one side of the document to prevent it from curling away from the platen. In the image scanning apparatus, the document retaining part prevents one side of the document from curling away from the platen by retaining the one side of the document. When a cover is closed over the document that is retained in this manner, the distorted document is pressed into complete contact with the platen surface. Accordingly, in the image scanning apparatus, the distorted document can be set at a predetermined position on the platen, and the distortion of the document can be corrected.
However, the distorted document is occasionally misaligned or bent on the platen of the image scanning apparatus, and such misalignment or bend may cause out of focus scanning of the document.
Namely, since the document retaining part is provided at one side only of the platen, the distorted document is retained at the one side where the document retaining part is provided, but not retained at the side where no document retaining part is provided. Therefore, the distorted document may curl at the side where no document retaining part is provided.
In the image scanning apparatus, when the cover is closed over a document that is partially curled away from the platen, the pressure of the cover may push the document away from the predetermined position on the platen, or bend the document. Hence, the document may be misaligned from the predetermined position or bent on the platen. Such misalignment or bend causes out of focus scanning of the document.
Such problems may occur in an apparatus having a platen such as a copy machine, a facsimile machine, a MFP (multi-functional printer or Peripheral), or other image processing apparatus.